Sin-Itiro Tomonaga

Tomonaga, Sin-Itiro, 1906–79, Japanese physicist, Ph.D. Kyoto Imperial Univ., 1939. He was a professor at Bunrika Univ. (now Tokyo Univ. of Education) from 1941 to 1956, then served president of the university until 1962. He subsequently was president of the Science Council of Japan and director of the Institute for Optical Research; he retired in 1969. He shared the 1965 Nobel Prize in Physics with Julian Schwinger and Richard Feynman for their fundamental work in the late 1940s and early 1950s on quantum electrodynamics, which quantifies the interactions between light and matter. The research had a significant impact on our understanding of the physics of elementary particles.